Heating apparatus.



w. cmmu. HEATING APPARATUS. y APPLICATION FILED NOV. 1.951915.

` 1,278,070', Patentedsept, 3,1918. A

2 SHEETS-SHEET 2- n Mii/72 6,6357

WILLIS c. MERRILL, or BOSTON,

MERRILL PROCESS COMPANY,

MASSACHUSETTS, ASsIGNoR 0E ONE-HALE To THE A CORPORATION 0F MASSACHUSETTS.

HEATING APPARATUS.

Application led November 19, 1915.

To all whom z't may concern.'

Be it known that I, WILLIS C. MERRILL, a citizen of the United States, and a resident of Boston, in the county of Suffolk and State of Massachusetts, have invented cer- A tain new and useful Improvements in Heating Apparatus', of which the following is a specification.

My invention relates to a new and useful heating apparatus especially adapted for the heating of asphaltic, bituminous or like materials where a high temperature is required to properly 'liquefy said materials to produce sufficient limpidity vto cause said materials to tiow freely. v

One object of my invention is to produce a new and useful improved fuel'oil heater adapted for use in connection with my im-A proved heating apparatus. A

Another object lis to provide for the relief of undue pressure exerted by the pump in circulating the heating liquid medium due to a cold mass of the circulating heating liquid or oil in the heating coil at the4 time of starting and heating and before the said heating oil is raised to Such a temperature as to flow freely for heating the entire mass of the material under treatment.

These and other objects are carried out by the apparatus herein described and shown in the drawings.

In the accompanying drawings which' illustrate a construction embodying my invention:

Figure l is a side elevation of the apparatus with the improved fuel oil heater partly broken away to illustrate the interior arrangement of the coil in the heater.

Fig. 2 is a side elevation of the tank or receptacle for holding the material to be treated, and is shown as broken away to illustrate the heating coil for liquefying the material within the tank or receptacle containing the material under treatment and also showing my improved liquid draw off device for the liquefied material.

Fig. 3 is a plan view of the tank or receptacle in which the material is treated or liqueed partly broken away to show the heating coil and'also the improved fuel oil heater broken away to illustrate its interior construction and arrangement. with the circulating pump and other coperating parts.

Fig. 4 is a vertical cross section through the fuel oil heater.

Specification of Letters Patent.

. material at its opposite end where it.

Patented sept.3,1918. Serial No. 62,411.

F ig. 5 is a sectional detail view with the side of the fuel oil heater broken away to illustrate the arrangement of the heating coil through which the heating liquid medium flows vfor heating the material under treatment in the tanker receptacle.

Like letters of reference refer to like parts throughout the several views.

In carrying out my invention as applied to asphaltic, bituminous or like materials the material is introduced into a suitable tank or receptacle B, through a nozzle B closed by a suitable cover B2, from a station-- ary storage or supply tank in which the is stored at from about 125 F to 200 It". or more. Or if desired the material for treatment or liquefac'tion may be introduced in a solid or semi-liquid form into the tank or receptacle B without preliminary heating and gradually heated to the n'ielting point in the tank or-receptacle B. as hereinafter described, and then raised tothe required temperature in the tank, thus avoid:- ing the use of the preliminary heating storage or supply tank. After the material has been introduced into the tank or receptacle B, the inlet nozzle B is closed after the asphaltic, bituminous or like material has reached the desired height in the tank or receptacle B.

From a suitable source, as the expansion tank L and feed pipe M. a pump or other circulating device K receives a liquid medium, as a suitable mineral oil. having a higher boiling point than 2120 F. and this heating liquid medium is circulated and heated to raise the trmperatnre of the Inaterial in the tank or receptacle B to liquefv the same to facilitate its easy flow. This pump K forces this heating' liquid medium through the pipe O2 into 'the pipe Dfwhieh connects with the heating coil C located in the fuel oil heater A and this coil C extends to the opposite end of the fuel oil heater A, as shown, and leaving this opposite end connects through the pipe S with the heating coil IV which is coiled and located in the tank or receptacle B and leaves the tank B connects with a pipe R connected to the pipe O leading to the circulating heating oil pump K operated by any suitable mechanism. Suitable hand valves N. E and Q are located respectively in pipes M, O2 and R for use as desired.

This heating liquid medium is kept in constant circulation through this closed circulating conduit consisting of the pipes O2 and D, the coil C, connecting pipe S, the coil XV and the pipes R and O back to the circulating heating oil pump K and brings the temperature of the contained asphaltic, bituminous or other material to about 300O F. to 400 F. The burner T receives a'suitable supply of gas and air through the pipes U and V which are controlled by hand or automatically if desired to regulate the same. The heating coils C in the fuel oil heater A are Wound as closely together as eX pedient, one-quarter to one-half inch apart, and in slight contact with the asbestos lining C arranged Within the t'wo shells forming the fuel oil heater A and prevents the radiation of heat from the interior of the fuel oil heater A, and this arrangement of the heating coils C brings into contact With the procl-V ucts of combustion extended heating surfaces through which the heating -liquid mediumcirculates and by slightly spacing the coils the excess of heat of the productsY of combustion circulates around the coils so that all the heating surface possible is in contact with the heat of the products of combustion. `By arranging the coils of the heating liquid coil C Within the heater close together the heatin liquid medium circulating through sai coils rapidly absorbs the heat units ofthe products of combustion as rapidly as possible with as little loss through Waste gases as possible.

AsV the temperature of the escaping gases from the stack A will always be in excess of the temperature to be attained by the heating liquid medium within the circulating coils, for instance, if a temperature of about 500o F. was desired in the circulating heating liquid medium then the temperature of the escaping gases should not be less than about 550 F., and in practice in burners used today by the applicant the temperature of the heat generated primarily by the burner T is in excess of 2500o F., which intense heat requires rapid absorption of the heat units bythe circulating liquid heating medium and rapid removal by the pump, with good insulation, as the asbestos C', to prevent ldestructionof the heater shell 'or container and to prevent radiation and the loss of heat and thereby producesan econi only in the utilization of the heat units from the products of combustion in the fuel oil heater. A.

The pipe F leads from the pipe O2 at the joint C tothe top of theexpansion tank L through the pipe l for the purpose of providing a short circuit of the circulating heating liquid medium or oil from the pipe Ol to the expansion tank L on the delivery or force side of the circulating pump K upon the obstruction of the norma circulation of the heating liquid medium or oil from any cause. This circulation of the heating liquid medium through the pump K, the expansion tank L and back and through the pump K is controlled by opening the valve G normally closed, and this short circuiting of the heating liquid medium or V'oil through and around the pump is to meet a condition of pump pressure which might arise from any cause, for eX- ample, to a cold Imass of the circulating heating medium or oil in the heater at the start ing of the apparatus and before the circulating heating' liquid medium or oil is raised to such a temperature as to flow freely under the forced circulation by the pump K for heating the entire mass Within the receptacle B. Upon the normal circulation being established, due to sufficient reduction in pressure, the valve G is closed so as to close the short circuiting of the heating oil through and circulating heating liquid medium through Vthe closed conduit to absorb the heat units ,struction and set at a pressure within safety to operate for any of the reasons above stated to cause the short` circuiting of the heating liquid medium or oil through and around the pump until the normal circu lation of the heating liquid medium or oil through the closed circulating conduit is re established, when the relief valve H automatically closesowing to the drop of the pump pressure which may have arisen from any cause interfering with the normal circulationof the Vcirculating heating liquid medium or oil.

By proi'iding these two safety relief devices to relieve the pump pressurethere is assured the-freedom of possibility -of accident from disruption or injury to the pump or other parts of the apparatus, as in the event of one of the valves being out of order, the other can be operated to -relieve the pump pressure and avoid accident.

The circulating pumpV K or other circulating mechanism is employedto keep this heating liquid medium in constant motion and in'its transit it isbrought in contact with high temperatures in the fuel heater A around the pump and force the such as would be produced by burning fuel y.

stored in this medium are transferred tov themass of asphalt or like material of lower i heat applied so as to carbonize the material A .tered in the use moved, and in the event under treatment because the heat units stored in this medium are under control and the temperature of the liquid heating medium at no time reaches a point that injures the integrity of the contained mass in the tank. Any suitable hand operated control or thermostatinay be used to regulate the de gree of temperature that may be desired.

Now by the use of this circulating oil heating fluid, a minimum pressure, say 5 to 10 lbs. per square inch, due to the friction of the heating fluid passing through the pipes and not due to the temperature of the circulating heating fluid, is maintained in the circulating coils, all the difficulties encounof steam are obviat'ed and the danger of foaming is also entirely re` of a leak occurring, the oil so escaping from the coils readily mingles and unites with the asphaltic material and does not cause foaming. Furthermore there is no pressure ivithiii the interior of the tank containing asplialtic material during the heating ofV this materialby this circulating oil for the reason that the heating medium is all contained in a tight circulating coil and is kept circulating, and furthermore the oildoes not expand except -through the expansion tank N provided for it on the exterior ofthe tank containing the asphaltic material. Now when the coil is full of circulating oil, any expansion of this oil in the conduit or coil is provided for by the expansion tank L into which vthe eX-I panded oil flows through the pipe M` and relieves the pressure in the system, so that the disruption or injury to the pump or other part of the apparatus avoided and constant supervision unnecessary, and this oil circulating produces uniform distribution of heat.

By connecting the feed pipe M to the suction side of the pump K, expansion of the circulating heating liquid medium or oil is provided for without interfering with thev circulation of the saine, and any lack of Circulating heating oil is supplied bythe tank L culating heating liquid mediunror oil if necessary, as the expansion. if any` of the circulating oil passing up through the pipe M does .not interfere with the feeding of the heating oil to the closed conduit for the circulating oil on the suction side of the pump l lf, on the other hand, the feed pipe M from the expansion tank L Were connected on the delivery or force side of to replenish from time to time the cir-v the pump K, any excess pressure due to the pump that might occur would tend to drive the circulating heating liquid medium.

`ingvheating fluid medium, as condensation does not take place and the heat units irnpaited to the circulating heating fluid medium are given up directly when brought in contact with the material to be heated.

o provision in this system of circulation is necessarily made as with steam to dispose of the condensation, and this circulating heating fluid medium being a non-elastic liquid differs from a condensible elastic fluid like steam and may be used over and over again for heating the material under treatment. By this forced circulation of the heating liquid medium by the pump, the heat units are uniformly distributed to the material under treatment, and further by this rapid circulation of this heating liquid medium, new surfaces of the heating liquid or oil are continuously presented to the heater and by' this forced circulation the heated liquid or oil is rapidly removed from the heater and thereby prevents carbonization of the heating liquid medium in the heater and the consequent crystallization of that portion of the heating oil conduit located in the heater.

This circulating heating oil used as a heating fluid medium in this system is similar to that used in'the apparatus shown in my co-pending application Ser. N o. 831,922, filed April l5, 191i, and has a boiling point above 212 liigher than the temperature required to properly liquefy the material, so that in its circulation it iiupaits tot-he material under treatment heat at high temperatures Without gasifying', as in the case of steam, and i F. and a carbonizing point to high temperatures without carbonization and the consequent deposit of carbon on the inner surfaces of the conduit. Such deposits of carbon on the interior of the heating conduit or coil prevent the easy floiv of the heating' oil and the ready transmission of heat to the material under treatment on account of the obstruction in the conduit of carbon deposits and of the increased density of the-circulating heating fiuid by the forming of carbon in the circulating heating oil,

and the integrity of the heating coil or conpoint is higher than the temperature required for the proper liquefying of the niaterial under treatment.

The temperature of ing fluid medium when in use averages about 400o F. to 500o F. which gives approximately a temperature of about 300 F. to 400 F. to the asphalt, lowfgravity oils or bituminous materials under treatment,

and this temperature is high enough to proi duce la suiiicient limpidity. in any known l form of asphalt or l them to loW freely before the carbonizing point of the asphalt or like materials or of thecirculating heating liquid medium has been reached, so that the integrity of the- -iiiaterials under treatment is not destroyed,

nor is there any loss or deterioration ofv the circulating heating liquid medium.

The metallic shell of the fuel oil heater A may be of thin and light metal because of the advantage possessed in the lesser .amount of metal to store any unabsorbed heat and thereby radiating to the coils containing the circulating medium after the apparatus is shut down, as it is desirable` to have the ap-` paratus cool off as rapidly as possible when not in use, and thin and light metal may be used in my improved heater for the reason that the rapidily circulating heating liquid medium or oil passing in the fuel oil heater rapidly absorb the heat units of the products of combustion and carry off the saine, and this rapid absorption is continued byv reason of new surfaces of the heating liquid medium being continuously forced through the coils of the heaterby the circulating pump.

In installations where insulating material like fire brick or heavy cast iron containers are used the effect of heating these coni tainers to a high degree during the operation of the apparatus is to store heat which later on When used with an apparatus of this character would radiate and heat the coils in the fuel oil heater to the injury of the circulating heating liquid medium containedin the heating coils should the system cease to operate or if shut down at the end of the Work and the -fuel oil heater Would not therefore readily cool oif.

YBy my arrangement of a heating coil With an asbestos covering on the exterior thereof, a thin and light shell may be used which not only prevents radiation of heat to the the circulating heat- I 'ke materials to cause through the coils C atmosphere, but avoids the storage of heat therein and the consequent giving 0H of. the i same after the apparatus is closed ydovvn or the machine should be stopped for some unavoidable reason.

In this fuel oil heater A the convolutions of the heating coil C are so arranged With respect to the burner T and to one another that their surfaces absorb the heat generated by the 'burner T, and the exterior of this heater A is insulated by the absorption of the heat units Within said heater, and the interior asbestos lining C assists in insulating the heater and prevents radiation of the heat from Within said heaterk to the atmosphere. This fuel oil heater A consists of a large chamber open at one end for the burner T and permits ready expansion of the burning gases and facilitates the absorption of the heat units created, While the other lend of thel heater A isreduced in diameter, With the coils C correspondingly reduced to fit therein,-and extends close up to the outlet stack A', While the' other end of the heating coilsC extends as close up as is practical tothe mouth of the heater Where the flame T at its greatest heat enters the heater from the burner T so that the heat entering is'at 'once taken up by the lining of coils through which the heating circulating liquid or oil is circulated.v This reduction in diameter of the fuel oil heater A causes a further impingement of the other gases and morerapid circulation of the heat units through the heater which heat units as they pass through the said heater are taken up and absorbed by the circulating oil Within the heating liquid coils C, and this heating liquid or oil. due to its rapid forced circulation by the pump, is kept in constant rapid circulation bringing nevsT surfaces of the heating oil continuously into contact With the high heat of the heater and preventing carbonization of the circulating liquid or oil within the heating coils and thereby further preventing the crystallization of the heating coils within the heater as the circulating heating liquid or oil is moved so rapidly that it does not reach a temperature Where it deposits carbon in the i heating coils, especially the coils in the fuel oil heater A. y

burning In this apparatus the circulating heating 4 be heated enters the heater 'it is at y.

in the products of combustion which is also at 1ts lowest temperature.

In the operation of the draw oifillustrated 1n proper degree of temperature to cause the asphalt or other like material -to low freely the valve Z is opened and the hottest material from the top of the tank passes down through the shell X and out through the 1 e A p lfter the material at the top of the tank has been drawn oft' in this manner the handle X4 is operated to raise the inner shell X to allow the liquefied'asphalt or other material in the bottom of the tank to flow through the perforations X2 in the bottom of the shell X and out through the pipe Y. After the material has been drawn off as desired the valve Z is closed and the parts are moved to their normal positions.

Having thus described the Vnature of my invention and set forth a construction em- Fig. 2, when the material has reached the bodying thesame, what I claim as new and desire to secure United States, is:

by Letters Patent of the i The combination with a cylindrical tank said coils having a pump to circulate liquid,

an expansion tank communicating with said conduit by pipes at both sides of said pump to permit of circulation against static pressure in one of said pipes, and a liquid medium lling said conduit and pipes and adapted when heated to be circulated by said In testlmony whereof, I have signed my name to this specification. f

WILLIS C. MERRILL. 

